In a process of building a pneumatic tire, a green tire is deformed by using a building drum. The building drum used for this process is provided with a plurality of segment plates, which are separated from one another in a circumferential direction of the tire. By radially expanding the building drum in the tire radial direction, the green tire formed by laminating uncured rubber members is deformed. In other words, by radially expanding the building drum in the tire radial direction, the green tire is lifted (refer to Patent Document 1, for example.)
However, if the coefficient of friction between the building drum and the green tire is high, the green tire does not smoothly slide on the building drum. Accordingly, the green tire is stretched locally in its portions near separating positions of the building drum. This results in a problem that the green tire is deformed non-uniformly in the circumferential direction thereof, and thereby the uniformity of the tire is deteriorated. Particularly, the existence of portions having a higher rigidity than others in the circumference of the tire makes the uniformity of the tire deteriorate pronouncedly. Such portions having a higher rigidity include splice portions where rubber members are overlapped and spliced.
[Patent Document 1] Japanese patent application Kokai publication No. 2001-113611